Tape punch machine

ABSTRACT

A tape punch machine in which, to assure accurate and reliable tape movement, a stepping motor for feeding the tape receives two pulses for each spacing increment of the tape. The punches are selected by interposers which are not released if the same punch function is to be repeated in successive cycles of the machine.

This is a division of application Ser. No. 485,906, filed July 5, 1974.

This invention relates to a cyclically operable tape punch machine inwhich the punches are selected by interposers in turn actuated bycommand signals.

A machine of this kind produces a program tape for controlling anothermachine or for controlling a circuit as in a teleprinter. The holespunched in the tape are small and the spacing between rows of holes isshort. Consequently, the components of the machine are tiny and arerequired to operate within very small space tolerances if there is to befast response to the command signals for high rate of tape production.

Small movements are involved, as already noted. The tape is advanced bya stepping motor to afford a spacing increment between rows of punchedholes. Virtually no tolerance is permissible for the spacing increment.It has been found not infrequently there is a variance in the spacingincrement responsible for misfunction when the punched tape is itselflater used to control another machine or another circuit. The variancewas found due to an oscillation in the stepping motor at the end of thelong pulse used to step the motor. An object of the present invention isto eliminate this variance and to obviate oscillation by stepping thestepping motor at least twice to produce the spacing increment in thetape. The particular control used may be employed concurrently in asecond mode which has to do with control over the interposers. Under andin accordance with the present invention the interposers, employed asselectors for punch actuation, are operated by solenoids. Operatinglevers are interposed between the solenoid cores and the relatedinterposers. A certain amount of voltage is required to shift the leverwhich operates the related interposer, but once this voltage is appliedan interposer may be held in its actuated position by a lesser amount ofvoltage, thereby prolonging the life of the solenoid in an instancewhere the function of a punch is to be repeated in successive cycles.Accordingly, it is another object of the invention to apply reducedvoltage for holding an interposer in actuated position during successivecycles of the machine. A related object is to enable step modulation ofthe applied solenoid voltage to be effected by the same control meanswhich controls pulses to the stepping motor.

In the drawing:

FIG. 1 is a plan view of the machine of the present invention;

FIG. 1A is an elevation of a sub-assembly of the machine;

FIG. 2 is a partial sectional view of the machine shown in FIG. 1, on anenlarged scale;

FIG. 3 is a sectional view on the line 3--3 of FIG. 2;

FIG. 4 is a sectional view on the line 4--4 of FIG. 2;

FIG. 5 is a fragmentary sectional view on the line 5--5 of FIG. 4;

FIG. 6 is a diagram which relates machine functions;

FIG. 6A is a fragment of a tape which may be produced by the machine;

FIG. 7 is a view at the back of the machine and showing an adjustinglever of modified form;

FIG. 8 is a timing diagram; and

FIGS. 9, 9A and 9B show punch configurations.

The tape to be punched is advanced from a supply reel, not shown,through a guide tray 20, FIGS. 1 and 2. To feed the tape, a feed wheel23 is afforded. The feed wheel has teeth 23T engageable with feedopenings in the tape. The feed openings are produced in the tapeconcurrent with code punching the tape as will be explained.

The tape is punched inside a die block 26 disposed between the guidetray and feed wheel. The tape is fed through a slot 27 in the die block.

To punch the tape, a plurality (nine) of aligned selectively operablepunches 29 are mounted for vertical movement in guide openings 31 in thedie block. Each punch has a sharp upper end 29E for perforating thetape. To locate the punches in normal position, the shank of each punchis formed with a shoulder 29S engageabe with a stop 32 mounted on theunderside of the die block.

To drive the punches, the lower or shank ends of the punches aredisposed in apertures 34 of a vertically movable driver bar 35. Thepunches are selected for operation by thin, flexible, blade-likeselectors or interposer slides 36, there being an interposer for eachpunch.

A separate, intermediate punch 29A, FIG. 4, is active in each cycle topunch a feed opening in the center of the tape.

The driver bar is slotted at 37, affording entry of the free ends of theinterposers. The slot intersects the apertures 34 so that each aperturehas a portion above and below the slot. The free end of each interposeris normally located at the entry of the slot 37. To guide theinterposers into the slot the driver bar is formed with beveled walls37A and 37B which afford an interposer guide throat divergent outwardlyof the slot 37 in the direction of the interposers. No other guide isnecessary for assuring entry of the free end of an interposer into theslot 37.

The interposers are controlled by solenoids S, FIG. 3, in a manner to bedescribed in more detail. When a solenoid coil electromagnet isenergized by a command signal the free end of the related interposer isextended into slot 37 to engage and support the lower end of a relatedpunch which is thereby selected for operation. Consequently, when thedriver bar 35 is elevated the supported, selected punch is actuated topunch the tape. If an interposer or slide remains retracted from slot37, the lower end of the related punch is not supported; it is idled andexperiences lost motion within the lower section 34A of its aperture 34when the driver bar is raised. To restore an active punch as an incidentto restoring (lowering) the driver bar, a punch restoring blade 38 issupported on the driver bar and engages a shoulder 39 on each punch.

The driver bar is operated by a crank assembly including an oscillatinglink 40 and a drive arm 42 which operates the link. The link 40 is inthe form of a yoke, having two fingers 44, FIG. 4, joined by a bail 45.The bail 45 is provided with an aperture enabling the link yoke 40 tooscillate on a support shaft 46, FIGS. 2 and 5, extended therethrough.The driver bar 35 is also of yoke form in that it has two dependent legs35A. The free ends of the link fingers 44, characterizing the link yoke,are provided with fixed pins 48 and 49 which loosely fit apertures inthe legs 35A of the driver bar 35. In this manner the oscillating linkand driver bar are loosely yoked to enable the driver bar and die headquickly to be changed in a manner to be explained.

The link 40 is oscillated to reciprocate the driver bar. To do this, theupper end of arm 42 is formed with an opening through which is extendeda pin 50 having its opposite ends supported by the link fingers 44, FIG.5. Arm 42 is oscillated by an eccentric 53 on a shaft 54 driven by apulley 55, FIG. 4, turned by a belt 56, FIG. 1, in turn driven by anA.C. motor, not shown.

The starting position of the driver bar may be adjusted within athousandth of an inch by a lever 60, FIG. 2. This adjusts the restoredposition of the punch elements. Lever 60 is supported for pivotalmovement on a fixed pin 61, FIG. 5. Lever 60 is clamped against theframe of the machine by a washer and screw 63, FIG. 2, and by a nut 64,FIG. 4, the latter being threaded on the end of shaft 46 which isextended through an elongated slot 66, FIG. 2, formed in the side frame67 of the machine, allowing adjustment. When parts 63 and 64 areloosened, the lever may be repositioned on support pin 61 as a pivot,raising or lowering the pivot shaft 46. Link 40 then pivots about pin50. Since link 40 supports the driver bar which in turn supports thepunches, the latter are raised or lowered relative to the path of thetape through the die block.

When a solenoid is energized, a lever 70, FIG. 2, is effective to thrustthe related interposer into the slot of the driver bar. The lever 70 isL-shaped and has one leg 71 pivotally supported on an edge 72 formed ina solenoid mounting bracket 74. Leg 71 is of magnetic material and ispresented to the core or armature 75 of the solenoid.

A pin 77 is supported by the other leg 78 of the lever 70. The pin fitsan opening in the related selector or interposer 36.

There is, of course, a solenoid S and related lever assembly 70 for eachinterposer. When a solenoid is energized, its lever 70 pivots clockwise,FIG. 2, thrusting the related interposer 36 into the slot of the driverbar 35. The throat 37A-37B serves as a guide, assuring the actuatedinterposer is presented to the punch to be selected.

A leaf spring 81, FIG. 2, restores an activated interposer and itssupporting slide. The free end of the leaf spring fits an opening 82,FIG. 3, in the interposer while the opposite end is secured to a supportpost 84. The spring is under tension as long as the interposer is in anactuated position and is effective to restore the actuated parts whenthe related solenoid is de-energized.

The wheel for advancing the tape is turned by a stepping motor 85, FIG.2, which drives a sprocket 86. The shaft of the tape drive wheel isprovided with a sprocket 87. A timing belt 8 connects these twosprockets.

It has been mentioned the restored position of the punches may beadjusted by lever 60. The idle or restored position of the interposerslides 36 may also be accurately adjusted by means of a fixed stop 88 atthe underside of the die block 26 and an adjustable stop 89 which issupported in a manner to be described.

In this connection it will first be noted the solenoid brackets 74, FIG.2, are secured as part of a solenoid sub-assembly to a mounting plate 90in turn fastened to the underside of a support plate 91. The interposersslide on the top of plate 91. The spring support member 84 includes aplate extension 84A overlying the interposer slides so that theinterposers are sandwiched between plates 91 and 84A. The interposerguides are essentially the springs 81 and pins 77. A detachable cover 92protects the interposers.

A vertical flange 94 is integral with plate 90, affording a mountingbracket fastened by hex head screws as 95 to the inside face of the sideframe 67 as shown in FIG. 2. Only one of the fastening screws 95 isshown. The flange 94 is slotted at 96 to receive the fastening screwswhich, when loosened, permit the mounting bracket 90-94 to be shiftedfore and aft, shifting the interposers at the same time.

As mentioned, the means for adjusting the restored position of theinterposers includes a fixed stop 88 and an adjustable stop 89. Thelatter is in the form of a bail or strap, FIGS. 2 and 3, supported onthe upper side of plate 91 for adjusting movement toward or away fromstop 88. This adjustment is made at the time of factory assembly.Afterwards the sub-assembly (solenoids, interposers and levers 70)supported by bracket plate 90-94 is positioned on the side frame, slidforward until stop 89 is against stop 88 and then the securing screws as95 are tightened. This sub-assembly, detached, is shown in FIG. 1A.

Thus, the pre-set position of the stop means 89 locates the selectorends of the interposers in the throat of the driver bar, spaced by thatdistance from the shank ends of the punches which will be mostresponsive for selecting the punches in accordance with the timingcharacteristics of each machine.

This arrangement also enables the punches and die block to be changed,as for instance when the punch diameter is to be changed or when thereis to be an alteration in the location or size of the punch 29A whichprovides the feed openings in the tape. Thus, by loosening the screws as95, the support bracket 90-94 may be shifted to the left, FIG. 2,affording access to the driver bar 35. The driver bar, it will berecalled, is supported on two pins 48 and 49, FIGS. 4 and 5, fixed tothe link fingers 44. This is a loose support, that is, the pins 48 and49 only loosely (slidably) fit the openings in the legs 35A of thedriver bar. Also, the driver bar and die block are joined by the stop32.

Consequently, when plate 91 and the interposers are shifted to clear theleft side of the driver bar, FIG. 2, and after removing a screw 98 whichsecures the die block in operative position on the side frame 67, thedie block and driver bar may be extracted as one unit merely by slidingthe legs 35A of the driver bar off the pins 48 and 49, to the left asviewed in FIG. 4. By removing stops 32 and 39, the punches may beextracted. Repositioning is in the opposite direction, the driver barlegs being slipped on to the pins. In this connection it will be noted,FIG. 4, the right leg 35A of the driver bar is shorter than the left,and the left finger 44 of the link 40 is flattened at 44' to facilitateextraction and slip fit insertion of the die block-driver barsub-assembly.

In operation, shaft 54 is constantly driven, which means the driver baris constantly reciprocated but no punch is active unless its solenoid isenergized. These and other operating and functional characteristics ofthe machine are shown in FIGS. 6 and 6A.

The leading end of a tape T in the course of movement through themachine is shown in FIG. 6A. Machine functions are diagrammed in FIG. 6.

As already noted, punch 29A, FIG. 4, once the tape is threaded onto thefeed wheel, is constantly active in successive cycles, which means itssolenoid is constantly active. Referring to FIG. 6, the feed punchmotion is shown as a sine curve (in and out of the paper) whichcharacterizes the successive, constant cycles of the driver bar. Totalmovement of the driver bar from bottom dead center to top dead center isonly about 0.120 inch, the punch travel being slightly less. The codepunches, when actuated, undergo the same motion, FIG. 6.

Further in connection with FIG. 6A, it is assumed that one of the codepunches is actuated in two successive cycles (A, B), that this samepunch is idled in the following cycle (space X on the tape) and that thesame code punch is actuated in the next cycle, punched hole C, FIG. 6A.

Since the tape will be undergoing feeding movement before the punchcommand signals are originated, two feed hole punches (1, 2) are shownin the tape in advance of the first code hole, A.

The feed wheel 23 is stepped by motor 85. The feed tape can only beadvanced when the punches are withdrawn from the paper. Consequently, asshown in FIG. 6, motor 85 is stepped only during the 180° period whichintervenes between the time the punches are withdrawn from the tape andtheir next entry into the tape. We have found that with the increment oftape advance involved between rows of holes (a spacing increment of onlyone-tenth of an inch) the inherent tendency for the stepping motor tooscillate at times produces an uncertain and inaccurate end point oftape movement when a single stepping pulse is used, whereas thisoscillation can be dampened and for all practical purposes removed,resulting in accurate and predictable tape positioning, by applying twostepping pulses to motor 85 for each increment (0.1 inch) of tapespacing movement.

Applying two stepping pulses to the stepping motor must, of course, betimed accurately to punch movement.

In accordance with the present invention this is accomplished by switchmeans timed and controlled by shaft 54, enabling the voltage applied tothe stepping motor to be varied. Referring to FIG. 7 a plurality ofsteel slugs are mounted on a disc 101 in turn secured to shaft 54 forrotation therewith. In FIG. 7 the slugs are shown as five in number,arbitrarily identified as 102-1 through 102-5.

The slugs rotate past a coil 104 and an associated permanent magnet 105which sets up a field with a certain flux density. As a slug moves pastthe coil 104, the magnetic flux density changes because the reluctanceof the magnetic circuit changes, and accordingly an enabling signal isgenerated much in the manner of a switch operated by a timing cam onshaft 54. While the sequence of the timing slugs may be changed fromwhat is given hereinafter, it may be assumed for purposes of disclosurethat switching slug 102-1 generates a control signal to switch from 12volts to 24 volts, slug 102-3 generates a control signal to switch from24 volts to 12 volts, and the fifth slug 102-5 results in generation ofa control signal enabling the voltage to be dropped from 12 volts tozero. The voltage referred to is the voltage source (not shown) employedto operate the stepping motor and to operate the interposer solenoids.

The magnetic circuit for applying accurately timed voltage changes mayalso be used to control operation of the interposer solenoids. Inasmuchas the feed punch 29A is always active and inasmuch as any one of thecode punches may be active in successive cycles when the tape is beingpunched, as shown in FIG. 6A, it becomes advantageous to hold theinterposers in actuated position when it is determined that the functionof a punch is to be repeated in successive signals. This conserves thesolenoid. The sensing means for determining a succession of punchfunction is not shown and plays no part in the present invention. It maybe simply noted a sensing means is employed to determine in advance if apunch active in a previous cycle is to be active in the next succeedingcycle, and of course this is constantly true of the punch for creatingthe tape advance holes.

It is assumed the voltage source (24 volts) imposed on a solenoid coilis required to operate the related lever 70 from a completely restoredor idle position clockwise to the position where it drives the relatedinterposer into the driver bar slot but considerably less voltage(twelve volts) is required to maintain that same lever and itsinterposer in punch selecting position.

Again, since the reference frame for all timing of machine functions isidentified with shaft 54, the slugs on disc 101 may be used tostep-modulate the voltage for the solenoids S between operating voltage,holding voltage and drop-out (zero) voltage. This is shown in FIG. 6.The voltage for the code punching solenoids may vary between zero, 12and 24. Twenty-four volts is required to move an interposer fromrestored to punch selector position, whereas only 12 volts is requiredto hold the interposer there. Consequently, the same timing slugs usedto pulse the stepping motor may be employed to step-modulate the voltageapplied to the solenoid coils as will be evident from FIG. 6.

A modified form of lever for adjusting the punch stroke is shown in FIG.7, lever 60A; its pivot is at 61A.

As shown in FIG. 6A the openings punched for advancing the tape are ofconsiderably smaller diameter than the so-called code holes, serving asa distinction in appearance. In FIGS. 9, 9A and 9B more detail ispresented. The feed hole F, FIG. 9A, may be centered on the code holes Cand consequently the stem S of punch 29A which presents the punch end iscentered with respect to the shank. The shank has a diameter D, the sameas the diameter of the typical code hole punch 29, FIG. 9.

However, a requirement is sometimes that the feed opening punched in thetape be of the so-called advanced feed hole orientation. This is shownin FIG. 9B where the feed hole F' is in tangent position compared to thecode holes C. Any change in this regard in the machine is easilyaccomplished under the present invention simply by changing the dieblock to accommodate a modified punch 29A', FIG. 9B, in which the stemS' is off-set to one side of the shank diameter D. The two punches, 29Aand 29A' are therefore supplied as a set, permitting interchange in thedie block.

We claim:
 1. In a cyclically operable tape punch machine, punchesselectable for operation, means to operate the selected punches,interposer slides moveable between a retracted and actuated position forselecting the punches, means including an electromagnetic means operableby an operating voltage of predetermined value to move an interposerfrom restored to actuated position in a cycle of the machine when itspunch is to be operated and means to apply a reduced holding voltage tothe electromagnetic means merely to hold an interposer in actuatedposition when that interposer is to be active in a cycle following thecycle in which it was actuated.
 2. A machine according to claim 1 havinga stepping motor for advancing a tape past the punches and through aspacing increment of tape movement between successive punched holes inthe tape and means for applying at least two pulses to the steppingmotor for each increment of tape movement.
 3. A machine acording toclaim 1 in which punch motion is derived from a rotary shaft, a disc onsaid shaft, steel slugs in circumferential displaced relation on saiddisc, a coil and associated magnet adjacent the path of said discscooperating with selected of said steel slug to generate control signalsfor switching the voltage applied to the electromagnetic means amongstzero voltage, operating voltage and holding voltage.
 4. A machineacccording to claim 3 having a stepping motor for advancing a tape pastthe punches and through a spacing increment of tape movement betweensuccessive punched holes in the tape and means for applying at least twopulses to the stepping motor for each increment of tape movement.
 5. Amachine according to claim 4 wherein selected of said slugs cooperatewith said coil and magnet to generate signals for so pulsing thestepping motor.
 6. A cyclically operable tape punch machine for punchinga tape in accordance with command signals and comprising:a plurality ofpunch elements arranged in a die block for advancing and restoringmovement; a reciprocal driver bar having apertures receiving the shanksof the punch elements, said driver bar having a slot intersecting saidapertures, said punch elements being supported to have the shank endsthereof exposed to the slot; interposers movable from a restored to anactuated position for selecting the punch elements and having theselector ends thereof disposed at the entry to said slot in the restoredposition; voltage-response interposer actuating means for actuating theinterposers to move the end of an actuated interposer into the slot tosupport a punch element for movement with the driver bar; and interposercontrol means, included in the interposer actuating means, applying aholding voltage for maintaining each interposer that has been actuatedduring one cycle of the machine in its actuated position through thenext cycle whenever its function is to be repeated in said next cycle.7. A machine according to claim 6 in which the interposer actuatingmeans includes a plurality of solenoids, one for actuating eachinterposer, and in which the interposer control means applies a givenoperating voltage to each solenoid to actuate its interposer fromrestored to actuated position and thereafter applies a substantiallysmaller voltage to that solenoid to hold such interposer in its actuatedposition.
 8. A machine according to claim 6, further comprising astepper motor for advancing the tape through a spacing increment betweensuccessive punched holes in the tape, and motor actuation means forapplying at least two signal pulses to the stepping motor for eachincrement of tape movement.